I have to agree with your friend Mark, as this is amazing! I use ranch when I make it. One tip that I think comes in handy... I mix the cheddar cheese into the mixture before I bake it. Once it's been sitting for a bit, it gets kind of hard to scoop it out because the cheese kind of hardens up. Yumm!!!!
I have made this several times and it is always the hit of the party, be prepared to have nothing left and people asking for more. I always use the Renee's blue cheese dressing though, and never a ranch dressing for buffalo dip. I always put it out with the tostito scoops. Its a guaranteed winner!!